/Engine/Source/Runtime/Core/Public/Math/Color.h
Converts from RGBE to a linear float color as outlined in Gregory Ward's Real Pixels article, Graphics Gems II, page 80. Implementation details inhttps://cbloomrants.blogspot.com/2020/06/widespread-error-in-radiance-hdr-rgbe.html
[FLinearColor](API\Runtime\Core\Math\FLinearColor) FromRGBE() const